PLEASE NOTE: Carriers change their plans and pricing constantly, so this may or may not be true for you when you order. We're just passing on the information we've learned from speaking to the carriers ourselves.

US Sprint is a somewhat unique when it comes to fax service. Fax service on Sprint is referred to as Wireless Web service and can be used without any active plan.

If you send a fax on Sprint without a Wireless Web plan, Sprint allows the call to go through and bills you for "Casual Wireless Web Minutes", which they bill at a rate of $0.40/min. As such, Sprint Treo users will probably find that they can fax right away. Charges are reflected within a few hours or faster on the Sprint website, so you can check pretty quickly what they're charging you.

Although $0.40/min is high, since faxes are generally under a minute, we find this route is actually cheaper for us than fixed plan minutes, and this is what we use in house. If you planned on faxing a lot, you should look into a bulk Wireless Web minutes plan.

Sprint users are invited to share their experiences and other information in this thread.

I just downloaded the latest beta version, 3.0.6 and tried to get it to work on my 650. I had it set up as a CDMA but nothing happened so i changed my config to show as 19200, class2.0, GSM, and left evrything else default and the fax came through. It was a bit misshapened (TEXT ELONGATED) but it worked. I guess i will find out what it cost me later. Just so you know.

That's an interesting experiment. However the setting should be Treo 650 (CDMA) for Sprint. You won't (well, shouldn't!) be able to receive a fax if you don't have it on CDMA. Sending might work though, that's a lot closer.

As for billing, generally Sprint seems to be $0.40/min for faxing if you don't have their plan, which in practice is tolarable for occasional faxing, and cheaper than the alternatives like Kinkos(!)

I have 700p with Sprint with unlimited Power Vision. CSfax is set to Treo650 (CDMA) at 19200, Class 2.0, CDMA, Use CTS/RTS, 60, ATZ using Tone at Hign speed.

I attempt sending and get Unable to read answer message. I check the log and find everything OK until the following lines in the log:
Class 2.0 Inq
CMD:AT+FMI?
IN:AT+FMI?_
ERROR_
CMD:AT+FMM?
IN:AT+FMM?_
ERROR_

Everything seems oOK until the program attempts ATDT which results in ERROR and Serial Timeout following with the MSG Unable to read answer.

hi is there any charge from sprint for using the csfax program? i have an unlimited data plan on my treo??

You'll have to check with your local Sprint rep to be sure, but Sprint plans seem to be fairly standardized nationwide now.

CS Fax uses the actual modem capability of the phone which Sprint calls "Wireless Web" service. That is NOT the same as packet data (Internet access) and the 'unlimited data' plan doesn't apply. You don't actually have to sign up for Wireless Web service; if you don't sign up for a plan, then Sprint bills $0.40/minute as "Casual Wireless Web Minutes".

In our case, that works out great. We haven't signed up for any plan at all, and even developing CS Fax and using the service constantly, it still is cheaper than any other option as most faxes transmit in under 1 minute anyhow. If you planned on faxing several times a day, every day, then I'd ask Sprint about a Wireless Web usage plan.